A multi Wide Area Network (WAN) Site-to-Site VPN router is a router that supports aggregating the bandwidth of multiple interconnections, e.g., WAN connections for accessing one or more remote private networks. In some implementations, each TCP/IP session is routed to only one WAN. In this configuration, a single TCP file transfer session can only utilize the bandwidth of one WAN connection on each end. For example, in a session based site-to-site virtual private network (VPN) connection VPN traffic is routed to multiple WAN connections between two sites (e.g., sites A and B).
In one implementation, M×N tunnels are initially formed between the WAN connections where M and N are the number of WAN network connections of site A and site B, respectively. Application TCP/IP sessions are then routed over the different tunnels. It is notable, however, that while a session based site-to-site VPN is able to utilize different tunnels for different sessions, a single download session in this type of connection is only able to utilize one tunnel.
In wireless communications, quality of packet transmission may be unpredictable, and packet drop rate may change frequently. This may reduce the quality of the overall packet transmission. Even if the bandwidth limit of each tunnel is high, the packet drop rate may not improve. A solution is required for utilizing multiple tunnels for increasing the probability of successfully transmitting data, which may be achieved by transmitting data packets more than once and also by transmitting packets that can be used for retrieving the original data packets.